Mosquitoes down, chances of West Nile virus up

Thursday

NORWOOD - Even though its dry and the mosquitoes are taking a break, don’t drop your guard or your insect repellant. These could become salad days for West Nile virus.

Even though its dry and the mosquitoes are taking a break, don’t drop your guard or your insect repellant. These could become salad days for West Nile virus.

Thanks to dry conditions since mid-June, the summer’s mosquito count is down across the state. That’s good in terms of lowering the risk of getting eastern equine encephalitis but it means a higher risk for the West Nile virus. Drier conditions are preferred by the particular mosquito that carries West Nile.

“Although there have been no cases yet of West Nile (this year), we are urging people to take preventive measures,” said Donna Rheaume, spokesman for the state health department.

David Lawson, assistant director of the Norfolk County Mosquito Control Project, said the mosquito situation could change weekly and that caution is needed. Larvae for the common house mosquito that causes West Nile have been found in some basins recently, said Lawson, who monitors mosquito counts in rain basins along roadsides.

The common house mosquito likes stagnant, even smelly water that tends to collect in drier weather.

“They don’t like the fresh, clean water that the rain would bring and that would flush the older stagnant water out,” he said. Rain literally flushes mosquitoes out of rain basins.

The mosquito that carries the virus causing EEE, on the other hand, does better in wet conditions.

So far, the state DPH has found no pools tested positive for West Nile Virus and just one pool tested positive for EEE.

Symptoms of West Nile virus include fever, headache, and body aches, often with skin rash and swollen lymph glands.

An outbreak of West Nile was identified for the first time in North America in New York during the summer of 1999. Massachusetts began testing for West Nile in 2000 and in 2002, there were two cases in Weymouth among 24 human cases in the state, up from three cases statewide in 2001. Three of the 24 people died; they were all older than 80.

In 2005, there were six cases in people, and one fatality. That was the first person to die from West Nile in the state since 2003, when 18 cases were reported and one person died.

Sue Scheible of The Patriot Ledger (Qunicy, Mass.) may be reached at sscheible@ledger.com.